Employing a nanny was once a hallmark of social status. Dual-income parenthood broadened demand for childcare. Now the internet and credit crunch are extending its popularity through "nanny-share" schemes.

Websites and agencies that specialise in matching up families so that they can pool the costs of taking on a nanny report a surge in business during the recession, spurred on by improved company benefits.

Dividing bills for at-home care can turn cooperative child rearing into a cheaper alternative than using nurseries while the expansion has been aided by the arrival of workers from eastern Europe. One estimate suggests the number of nannies working in the UK may have grown from around 115,000 in 2003 to as many as 160,000 now.

What was once the cossetted childhood experience of a privileged few is now becoming more common.

The ease with which the latest generation of parents navigates the internet makes the process of halving childcare bills as simple as online dating, according to one agency involved in matching up families.

Nannytax, a firm that helps parents sort out tax liabilites, says the percentage of its work involving nannies jointly employed by more than one family has risen sharply over the past 18 months, from 17% of its workload to 24%. The recession, it believes, is driving more parents out to seek work and forcing others to share their nanny with another family as an alternative to firing them.

"It is becoming more affordable to hire a nanny, particularly with arrivals from eastern Europe," explained Ben Black who runs the website NannyShare. "And people are more comfortable meeting online.

"The other big trend is more flexible working, with people working from home or doing fewer days a week. People have far more need for childcare support, particularly in the south-east where grandparents are often more distant.

"We did a survey of 25 agencies and came up with an estimate of up to 160,000 nannies working in the UK now. We have had 50,000 nannies on our books over the past five years."

His colleague, Justin Jeffries, added: "We have seen our business increase by a third this year. If you think of it as a dating website, the principles are the same. You want to find the best match.

"Hiring a nanny is still considered the best quality childcare option but on your own in London you would be paying more than £30,000. Like this, you can share the costs."

A rival website, Nannysharers, also reports an upturn in business. "There's been a big surge," said Theresa Byrne, who runs the site. "It's a lifestyle change that's spreading across the country."

Åsa Nilsdotter, of Nannytax, said her company has had its busiest summer on record. "We are seeing a lot more mothers returning to work. Sharing a nanny is highly cost effective."

The growth in cooperative child rearing is also transforming the lives of nannies, she argues, making the profession more independent and salary-focused – with fewer nannies prepared to take up live-in placements.

"Most nannies are still British; more are now living out. It's no longer so much an upstairs/downstairs relationship. They now want a chance to get on the property ladder rather than the perks of gym membership or going on holiday abroad with their family."

According to the company, 85% of nannies now live outside the home where they work. Nanny-sharing arrangements are not only common in London and the home counties, the firm says, there are also "areas with a high density of nanny employment" in Cheshire, parts of Yorkshire, and Manchester. NannyShare reports brisk business in Birmingham and Essex.

Nannytax says the government has been slow to respond to the change. While childminders are subject to compulsory Criminal Record Bureau checks, and must have personal insurance and be Ofsted registered, those requirements do not apply to nannies. The childcare industry suspects the issue is dismissed as peripheral and relevant only to the wealthy upper class.

A spokesperson for the Department of Children, Schools and Families said: "Nannies are not required to register with Ofsted; however, we would encourage them to join the voluntary part of the General Childcare Register (GCR)."

Nanny sharing is likely to impose heavier workloads, but greater responsibilities also bring greater rewards, with combined incomes from two families. Some nannies work part of the week with one family and part with another; more often they bring children from two families together in one home.

Lisa Wilkins, 33, a nanny working in Tooting, south London, favours the new approach. "I have been doing nanny shares for the past six years," she said. "I always like to work from one home. It's easier to settle in.

"I look after three children. One is an only child so she gets the benefit of having siblings. I've never done live-ins. My partner works in banking. Sometimes I feel embarrassed, as though my job is frowned upon. I was once called a glorified baby-sitter. But I always wanted to work with children. It's enabled me to work abroad. I would like people to recognise it as a proper profession.

"The families we worked for once were very upper class. Now it's more middle class. They can afford it because they are sharing the cost. More people can have the best type of care for their child."

Fiona Jull, who lives in Wandsworth, uses a nanny-share arrangement. "I just assumed I would put my baby into nursery when I went back to work. Then I looked at having a nanny but realised it would cost half my salary so I decided to share. I found a family – through a website – around the corner. I drop my son off two days a week and he's here two days a week."